On the ocean, boats are a whole lot more fun.

 I dunno about a lake.

 Boats are fun because you're away from the shore, the diving is usually
better, the trip is fun.

 Plus, learning how to boat dive, especially being considerate of your fellow
divers, is not something you want to do OJT.

 You may well wind up next to a diver like me, more than willing to give you
the benefit of my opinion.
               

                                   Popeye  
  Man is certainly stark mad. He cannot even make a worm,
           and yet he will be making gods by the dozens.

Was there anything about the shore dive that makes you prefer a boat dive for the OW
dives? As Lee points out, the type of dives isn't the right criteria for deciding
between the two shops. You can always do your checkout dives elsewhere with a
referral. We usually suggest doing them at home, but supposing you were going to do
your dives on a vacation to the tropics, which shop would you use for the lessons at
home? That's the one you should use, and then do your dives with them by whichever
method they choose, unless there's a compelling reason to make a different decision.

The points about boat etiquette are relevant, and regardless of how the checkout
dives are done your instructor should cover the topic.

Furthermore, if you're overweighted, your family will know why you died.

I may not have needed it, but I think it gave me quite a bit better
perspective and a real edge on experience for future boat dives.